1. Field of the Invention
This invention relates to magnetic recording mediums such as magnetic tapes, magnetic disks and the like and more particularly, to back-coated magnetic recording mediums having a specific type of lubricant in the back coat layer.
2. Description of the Prior Art
Recently, home video tape recorders have been widely in use. Magnetic tapes used for these recorders are run while contacting, under tension, a number of guide pins in a loading mechanism of the recorder.
In order to improve the runnability of the magnetic tape or to reduce a coefficient of friction of the magnetic tape, there has been proposed formation of a back coat layer such as described in, for example, Japanese Laid-open patent application Nos. 52-73703, 58-41420 and 59-5428.
More particularly, a magnetic recording layer is formed on one side of a non-magnetic support and a back coat layer is formed on the opposite side. The back coat layer is made of a composition which comprises a fluorine-modified silicone oil, carbon black and barium sulfate. However, this type of back coat layer is not satisfactory particularly with respect to the runnability for rewinding at low temperatures.